/**
 * Created by 王景华 on 2020/12/26 8:37 下午.
 */

#include <stdio.h>

int main(void){
    float a, b;
    b = 2.0e20 + 1.0;
    a = b - 2.0e20;

    printf("%f\n", a);

    return 0;
}